The present invention relates generally to toner image production machines, and more particularly, concerns a modular toner image production machine including distributed module-specific control subsystems having in situ fault recovery-assist user interface devices for providing in situ recovery assistance for remote modules, and for enabling recovery-while-running isolation for redundant modules.
In a typical toner image production machine such as an electrostatographic reproduction machine, a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light image of an original document being reproduced. Exposure of the charged photoconductive member selectively dissipates the charge thereon in the irradiated areas. This process records an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith.
Generally, the developer material is made from toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules to the latent image forming a toner powder image on the photoconductive or image bearing member. The toner powder image is then transferred at an image transfer station, from the photoconductive member, to a copy substrate such as a copy sheet of paper.
Thereafter, heat or some other treatment is applied to the toner particles at a fusing station to permanently fuse and affix the toner powder image to the copy sheet or substrate. The copy sheet or substrate typically is fed automatically from a stack supply thereof, along a sheet transport path that includes a sheet registration subassembly, to the image transfer station where the toner image is transferred from the image bearing member onto a first side of the copy sheet. As discussed above, after such toner image transfer, the copy sheet is moved along the sheet path to the fusing station of the machine where the toner image is fused and affixed to the copy sheet. In machines with duplex copying capability, the sheet path usually includes a sheet inverter, and the copy sheet after leaving the fusing station, is inverted at the inverter and refed to the transfer station in proper orientation for receiving a second toner image on a second side of the copy sheet. In either case, the copy sheet with the fused toner image or images on it is then forwarded to an output tray or finishing station. High quality output copies typically require proper and high quality registration of the toner image or images on the copy sheet.
To achieve such registration, the copy sheet must be transported in a timed and registered manner to the sheet registration subassembly and to the transfer station each time, and sheet drive mechanisms along the sheet path have to function without slippage. Presence and proximity sensors can be used for assisting the achievement of such proper and timed registration of each copy sheet. Typically, any failure of a copy sheet being transported along the sheet path to activate any of the above sensors at a control point, in time or space, usually registers as a machine error. Detection of such an error usually results in a copy sheet stall or jam along the sheet path, as well as in a machine shutdown, and in a call or alert for an operator to remove or clear the stalled or jammed copy sheet, wherever it may be, along the sheet transport path.
Sheet handling systems as well as developer material systems within such machines usually come as xe2x80x9cworks in a drawerxe2x80x9d because of the benefits they offer for operator services such as clearing jammed or stalled sheets contained entirely within the subsystem. Such drawer designs are particularly employed for electrostatographic machine subsystems such as the fuser and post-fuser sheet inverter subsystems that ordinarily include hidden sheet paths that are hard or unsafe to access. With such designs, to subsystems such as the fuser, inverter, duplex and/or registration transports are mounted on a drawer or platform on rails and slides which enable the subsystem(s) to be pulled out of, and pushed back into the machine. Typically, each such subsystem includes sensors and switches that may from time to time fail and require service. Additionally, each such subsystem, is made movable in and out of the machine, relative to other fixed portions or components of the machine. As higher and higher speed machines are made to have more and more features and more and more such subsystems or modules, more and more components will become packed within each subsystem or module. As such, problems are very likely to occur stopping production, and the machine ordinarily will need servicing.
Conventionally, when problems occur that cause production to stop prior to successful task completion, as disclosed for example in U.S. Pat. No. 4,500,971, centrally located devices such as the machines main user interface have been suggested for the purpose of providing users with an alarm notification of the problem Such conventional devices may even include more information such as fault status notification as well as instructional support for resolving the problem (e.g. fault recovery information). Typically, in these devices this notification and recovery information is presented through a visual modality for example via an alphanumeric display device.
In large modular machines, the entire machine usually shuts down when there is a need to use the one centrally located User Interface to assist in the recovery of the faulty module. Additionally, in the case of most modules, operators have to step back and forth to constantly review information at a greater risk of misreading errors. Because such large modular machines are located in high volume copy production areas that tend to be very noisy, centrally located auditory warning and information devices are not that much better.
In accordance with the present invention, there is provided in a modular toner image producing machine having plural modules including redundant modules. The modular toner image producing machine comprises (a) a photoreceptive module including a movable endless photoconductive member having an image bearing surface; (b) toner image forming modules is for forming a toner image on-the image bearing surface, each of the toner image forming modules including module-specific fault detectors; (c) at least one sheet feeding module for feeding a copy sheet to receive the toner image from the image bearing surface; (d) a fusing module for heating and fixing the toner image onto the copy sheet forming a hard copy; (e) at least one finishing module for preparing and arranging a series of hard copies into sets thereof for removal by an operator; and (f) a control module including a main electronic control system having a centrally located user interface device, and distributed module-specific control subsystems, each having a dedicated module and being connected to the main electronic control system and to module-specific fault detectors of the dedicated module, and each of the module-specific control subsystems having a fault recovery-assist user interface device located at the dedicated module and remotely from the centrally located user interface device for providing in situ recovery-assistance for each the dedicated modules, and for enabling recovery-while-running isolation for a redundant dedicated modules.